Water discriminating fuze



April 23, 1957 Filed Dec. 7, 1949 H. c. FILBERT, JR., ET AL- 2,789,506

WATER DISCRIMINATING FUZE 5 Sheets-Sheet 1 lol He I07 24. H4 89 m I H.C. FILBER'IIJI:

Hul PLUMLEY April 23, 1957 H. C. FILBERT, JR., ET AL WATER DISCRIMINATING FUZE 5 Sheets-Sheet 2 Filed Dec. 7, 1949 .2 5 mm on 3 3 H.C.FILBERIJn .H.J.PLUMLEY I W W mum Mw wKmm v m. w R L w...

April 23, 1957 h H. c. FILIBERT, JR., ET AL 2,789,506

, WATER DISCRIMINATING FUZE Filed Dec. 7. 1949 5 She'ets-Sheet 3 H.C.FILBER'I;J: H.J.PLUML EY April 1957 K H. c. FILBERT, JR., ET AL 2,789,506

- WATER DISCRIMINATING FUZE I Filed D60. 7, 1949 5 Sheets-Sheet 4 I I Hm (Mew-w April 23, 1957 H. C. FILBERT, JR.. ET AL WATER DISCRIMINATING FUZE Filed Dec 7, 1949 5 Sheets-Sheet 5 :g llt'a ammun H.C.FILBER'IJr. H.J.PLUMLEY Mewg Uni e t Pew F WATER DISCRIMINATING FUZE Howard C. Filbert, Jr., Baltimore, Md., and Harold J. Plumley, Washington, D. C.

Application December 7, 1949, Serial No. 131,651

14 Claims. (Cl. 10270.2)

(Granted under Title 35, U. S. Code (1952), sec. 266) This invention relates to a fuze for a bomb for detonat ing an explosive charge therein and more particularly to a water discriminating fuze in which a movable magnetic core assembly is employed for increasing the sensitivity of the fuze particularly upon impact of the bomb with the surface of a body of water, the firing of the fuze being accomplished by a change in. the magnetic field within a coil as a result of the movement of the magnetic core assembly in response to the aforesaid water impact, or impact with a target as the case may be, or as the fuze approaches a target, and in which means are employed to delay the firing of the fuze selectively in accordance with the rate of approach of the fuze with respect to the target and the material of which the target is composed.

Magnetically controlled fuzes of the type heretofore devised for firing an explosive charge have proved to be not altogether satisfactory under all conditions of service for the reason that such devices lacked water impact sensitivity and only functioned on water impact when dropped at a considerable'altitud'e from an aircraft in flight.

In the device of the present invention the water impact sensitivity thereof has been increased considerably over the prior art devices by employing a floating magnetic core assembly in lieu of a rigid magnetic assembly as employed heretofore and disclosed and claimed, for example, in the copending application of H. J. Plumley et al. for Fuze For A Bomb, Serial No. 541,257, filed June 20, 1944, now Patent No. 2,719,486, issued October 4, 1955. The trailing end of the magnetic core is arranged in spaced relation with respect to a ferrous body secured to the bomb and having a coil arranged therein with the axis thereof in substantial alinement with the axis of the permanent magnetic "core, the core assembly being supported by the ferrous body and movable with respect thereto. The core assembly comprises a segmented core structure composed of permanent magnetic material such, for example, as a material known in the art as Remalloy and having a coil composed of a relatively small number of turns of wire arranged about the forward end of the core and encased in suitable insulating material.

The coils are respectively connected to a pair of electroresponsive deto-nating devices by a firing circuit having a shock proof arming switch therein adapted to close the circuit when a propeller operatively connected to the arming mechanism of the fuze has made a predetermined number of revolutions during the free flight of the bomb through the air. Each of the electroresponsive detonators is adapted to provide a predetermined time delay be tween the ignition thereof in response to a firing impulse received by the aforesaid firing circuit and the firing thereby of a detonating cap whereby the time required to fire the cap in response to the firing impulse received from the front coil is less than the time required to fire the cap in response to the firing impulse received from the rear coil, as will be more clearlyapparent as the description proceeds. i

ICC

The percussion cap is not brought into firing relation or alinement with the electroresponsive detonators until 3 the arming switch has closed the aforesaid firing circuits.

With the detonating cap in the armed position, an explosive train is established between the detonators anda booster charge whereupon the booster charge is adapted to be fired by the electroresponsive detonators. The fuze of the present invention is adapted to be fired by a change in the number of flux linkages of the front coil as the fuze moves into close proximity to a target composed of magnetic material such, for example, as the deck of a vessel.

ing on the fuze will cause the magnetic assembly to move rearwardly against the action of the supporting spring therefor, whereupon the air gap between the magnetic core and the aforesaid ferrous body is decreased and thus the resulting increase in the number of flux linkages of the rear coil with the field set up by the permanent magnetic core causes a firing impulse to be generated by the reareoil; The impulse is of sufficient strength to fire the slow operating detonator thereby delaying the firing of the bomb until the bomb has traveled for a predetermined period oftime such, for example, as .25 secend after the firing impulse has been received. Furthermore, in the event that the bomb strikes a nonferrous target with suflicient force to dislodge the permanent magnetic structure from the ferrous body supporting the rear coil, or with only sufiicient force to disarrange the spaced relation of the magnets with respect to one another, or to partially demagnetize the magnetic core, a

firing impulse will be generated by the rear coil and thus the bomb will be exploded in predetermined time delayed relation with respect to impact of the bomb with the target.

One of the objects of the present invention is to provide a new and improved water discriminating .bomb fuze controlled by a variation in the magnetic field adjacent thereto and having means for increasing the sensitivity thereof in response to impact of the bomb with. the surface of a body of water.

Another of the objects is the provision of a new and firing the bomb in predetermined time delayed relation with respect to the moment of impact of the bomb with the surface of a body of water and for firing the bomb in difierent time delayed relation with respect to the moment of impact of the bomb with a target vessel or the like.

Another object is to provide a new and improved magnetically controlled fuze for a bomb in which the fuze is fired by a variation in the magnetic field adjacent thereto as the fuze moves into close proximity to a target 1 and irrespective of the angle of impact of the fuze with respect to the target.

A further object is to provide a new and improved fuze for a bomb in which the fuze is fired in response to a sudden decrease in the reluctance of the magnetic circuit adjacent the fuze or in response to a decrease in the mag- 1 I netomotive force in the magnetic circuit within the fuze. K A still further object is to provide a new and improved fuze for a bomb which is economical to manufacture,

. Patented Apr. .23, 195.7

In the event that the bomb strikes the surface of a body of water, the force of the impact therewith act- 1 3 reliable-in operation and which possesses all the qualities of Tuggedness'and" dependability in service.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to thefollowir gdtailed-description when considered'in-connection with the accompanying drawings, wherein:

Fig. 1 is aview in elevation of a bomb em lo ing the fuze=andtlie impact responsive means'of 'the present 'in ventionaccording to a preferredembodirnent thereofj Fig. Z'isanenlargedview'partly-in section and partly broken away of the haze of Fig. 1';

Fig.: 3 is a longitudinal seetiontu viewof 'tnefnze in. an armedconditio'n;

Fig; 4 is an elevational view of the fuze partly broken awayand'zpartly' insection thereby to-"sho'vv the pair of electroresponsive detonat-ing devices and the electrical conductors connected thereto;

Fig. 5 is an'enlarged: sectional view taken on the'line 5--5i-of Big. 2;

Fig. 6"is. a sectional view taken on. the line. 6'6. of Fig: 2;

Fig-.27 is .a fragmentary sectionalview taken on the line 7--7' of Fig.5;

Fig. 8 is an enlarged fragmentary sectional view of the fuze showing the arming switch. and arming plunger in an initial safe position;

Figs.;9, 10, 11 and 12 are detail sectional views of the shocle proof arming switch employed with the fuze of the present invention and taken on lines'9.-9, 1010, 1111 and.12-12 of.Fig. 8 respectively;

Fig. 13 is a-view of the fuze partly broken away and partly in section and taken substantially on the line 1313 ofFig. 10;

Fig. 14 is aperspective view ofone of 'thecontact ele mentsemployed with the switch; and

Fig. 15 shows .in diagrammatic form the electrical circuits. and instrumentalities employed for firing the deto nat'ors.

Referring now to. the drawings for a more complete under'standingof the invention and. more particularly to Fig. 1 thereof, there is shown thereon a bomb indicated generally by the numeral 11} comprising a casing 11 to which is secured a plurality of guide members 12 by means of which the bomb is adapted to bereleasably supported byan aircraft in flight. An arming wire 13 connected to the airplane as by a static line secured tothe eye bolt 14 is preferably employed toprevent rotative movement of the propellers 15 and 16 associated with a hydrostatic tail fuZe 17 and with the fuze 18 of the present invention respectively. The fuze comprises .a member 19. securedto thenose of'the bomb in any suitable manner. such, for example, as by threading the parts together, shoulder 21 beingformedon the member 19 and havingabutting engagemeut'wi'th a complementary shoulder on the bomb provides means whereby the fuze'is more securely attached'to the nose of the bomb, Fig. 1. The member 19 is composed'of any magnetic material suitable for the purpose such, for example, as iron or low carbon steel and is provided with an annular recess or Well 22 having disposed therein a coil '23, hereinafter referred to as the rear coil. An. external electrical connection to the coil 23 is established by means of a pair of conductors disposed within a duct 24 formed in the member 19 and extending inwardly and rearwardly from the recess 22, a similar duct 24 being provided within themember 19 for oneofa pair of conductors connected to a front coil 29, the other conductor beingdisposed in duct 24, Fig.3. The front or forward portion of the member 19 is formed in a plane surface 25 and is normally spaced from one end of aplurality of permanent bar magnets zdcom-posed of magnetic ma-, terial suitable for the purpose and having high remanence anda relatively high'permeability such, for example, as a' material'k'nown in the art as" Remalloy. Each ofth'e' bar magnets is'preferabl'y square inycross'sectionand a'r- .rangedin'abutting relation with 're'spect'to the adjoining bar magnets and all of the bar magnets are poled in the same direction: Themagnets26 are maintained'in' spaced relation with respect to the member 19 by a plurality of spring fingers 27 formed on an annular member 28, Figs. 2, 5 and 7.

As shown on Fig. 6, twelve permanent magnets are employed to provide a unitarysegmented core structure disposed about arod 31 composed of nonmagnetic material such, for example, as brass and securely maintained in the unitary'structure' by a moldedplastic sleeve 32' formed about the magnets. The plastic sleeve 3'2'may be composedof any material .suitable for the purpose such, for example, as a material composed of' cellulose butyro acetate and known.'in-thetrade' as Tenite II. The coil 29 is also molded within thesleeve, and hereinafter referred to as'afront" coil arranged about the'forward'end of the magnetic structure or core 33 comprising the aforesaid plurality of bar magnets. The coil is provided with a pair of conductors molded within the sleeve 32 and extending rearwardly along the magnetic structure and through theducts'24 anduzwrespectively, and insulated therefrom for establishing-anelectrical connection to coil 29, Fig. 3. The rod 31 'islsecured to the support or member 19 asJby dowel" pini34, Fig. 3 and provided with a bore 35 axially'1 arranged'therein. within'which is slideablydisposedaa plunger'or rod36:

The sleeve '32 is movably attached to the member 19 as by a coupling 37 having a flange 38 arranged in abutting engagement with a shoulder 39 formed on the sleeve. The coupling 37, it will be noted, is composed of magnetic material such; for example, as iron. The support 19 isalso provided with an annular'recess 41 for receiving-a: suitable gasket 42 composed of brass or the like thereby toprotect the :rear coil. from injury and also to provide a bearing surface for the spring fingers 27, Figs. 1 and 2.

Threaded within the outer end of the bore 35 is a stud shaft 43- provided with a collar 44 normally in abutting engagement with the rod 31 and having one end thereof in engagement with the-rod 36-when the .fuze is an an unarmed posit-ion, Fig.,2-. The shaft 36 is slideablydisposed within a bearingmember 45. secured to the tubular member 31 by apin 46, the member 45 having-a pair of bumpers or cushioning devices4 7 inabutting engagement with the respective endthereoffor absorbing the shock during movement ofthe shaft-or rod 36. A gear 43 is supported bythe shaft .43. rotatable with respect thereto. The gear, however, is prevented from rotating by a pin 49 secured thereto and slideably disposedwithin an aperture. 51 arranged within the front endportion of the tubular member 31'. I There is also provided a gear S2v slidea-bly secured to the shaft 4-3b'yaspline 53 or thelike and thus the gear 52is' adapted to impart rota't-ive movement to the shaft 43. It will be understood, however, that thegearSZ, is provided with one more tooth than the number of teeth on the gear 48 and arranged on the same pitch diameter as the teeth on gear 48. There is also rotatably secured to the'shaft 43 a hub 54 to which is secured a shield or guard 55; having a stud shaft 56 thereon for supporting for rotation anidle gear 57in continuous mesh with gears 48 and 52 From the'foregoingit will be apparent that a structure has'been disclosed'in'which the shaft 43 is constructed and arranged'to rotate'at 'a greatly reduced rate of speed with respect to the rotation. of the hub 54 by reason of the planetary gear arrangement disclosed. The hub 54 is rotatably secured to the shaft 43 by a screw 58 and washer 59. The hub 54 receives and supports a cap 61 having the propeller 1o secured thereto as by pins 62, the pins being provided with enlarged heads adapted to engage complementary recessed portions 63' Within the hub' 54.- By this"arrangement rotative movement is irripartedto the-hub as there'sult' of the pressure of the'air againstthe propeller'ld during 'thefree flight of the bomb toward a target.

Thehub'54' is restrained from rotation during the transareaene portation of the bomb by the aircraft by the aforesaid arming wire 13 whichis normally arranged within an aperture 64 of one of a pair of members 65 and one of a pair of complementary apertures 66 arranged within the guard 55. The members are secured to the sleeve 32 in any convenient manner, such for example as by screws 67. By providing the pair of L-shaped members 65 diametrically arranged on the sleeve 32, the guard 55 may. be secured thereto by a cotter pin prior to the installation of the bomb on the aircraft, thereby preventing rotative movement of the 'hub during the handling and transportation of the bomb to the aircraft. It will be understood, however, that when the bomb is releasably secured to the aircraft, the cotter pin is removed and the arming wire 13 is inserted within the aforesaid apertures 64 and 66.

Secured to the rear portion of the fuze as by threaded engagement therewith is a tubular container 68 having one end thereof closed at '69 thereby to receive and support a booster charge 71, the booster charge being arranged within the container between the end wall 69 and an adapter 72. The adapter is secured to a cylindrical member 73 as by screws 74, Fig. 3, the member 73 being secured to the support 19 as by screws 75, Figs. 2 and 8. The member 73 is composed of insulating material suitable for the purpose such, for example, as Bakelite or the like and recessed to receive a pair of electroresponsive detonating devices 76 and 77, the detonating devices extending into a pair of recessed portions 78 and 79, Fig. 4, formed in the adapter 72 and in communication with a transverse bore 81 arranged within the adapter.

A detonator holder 82 is slideably arranged within the bore 81 and urged toward an armed position by a spring 83 having one end in engagement with a plate 84, the other end thereof being in engagement with the detonator holder, Figs. 2 and 6. The holder or plunger 82 is releasably locked in the initial safe position, Fig. 2, by a slideable rod S having one end thereof in abutting engagement with the plunger and disposed within a bifurcated portion formed therein. The rod 85 is molded in a tubular member 86 composed of suitable insulating material such, for example as Bakelite and having a sleeve 87 composed of electrical conducting material molded on one end thereof.

As shown on Fig. 2, the rod 85 is maintained in locking engagement with the detonator holder 82 by rod 36 and stud shaft 43 and movement of the holder will not occur until the propeller 16 has made a predetermined number of revolutions during the free flight of the bomb toward the target. The member 86 is slideably arranged within a well or bore 88 formed in the support 73 and a bore 89 formed in the member 19 and is adapted to be urged to an armed position as the propeller rotates. A spring 91 having one end in engagement with the bottom wall defining the bore 88 and the other end thereof in engagement with the member 86 is adapted to urge the member continuously toward an armed position. As the member 86 moves to an armed position, the rod 85 moves out of locking engagement with the detonator holder 82 whereupon the holder is released and is moved within the bore by the spring 83 to an armed position, Fig. 3. When the detonator holder 82 is in the armed position, a sensitive detonator 92 arranged therein is moved into alinement with a lead-in charge 93 thereby establishing an operative explosive train between the detonator and the booster charge 71. Furthermore, with the detonator holder 82 in the armed position the sensitive end of the detonator 92 is brought into operative relation with respect to the electroresponsive devices 76 and 7'7.

The detonator holder 82 is provided with a dowel pin 94 slideably disposed within a slot 95 arranged within the adapter 72 and parallel to the bore 81 thereby to prevent rotative movement of the holder with respect to the adapter. The holder is also provided with an annular shoulder 96, Fig. 2, adapted to be engaged by a pair of spring actuated detents 97 slideably arranged within the,

adapter when the plunger 82 is moved to an armed'position, the detents being continuously urged toward the plunger by a pair of springs 98, Fig. 3.

The detonating devices 76 and 77 are arranged to pro vide a predetermined time delay between the operation of the electroresponsive element thereof and the firing of i the sensitive detonator 92 thereby, the detonating device 76 being arranged to provide a delay of approximately .25 second and the detonating device 77 a delay of .01

second between the detonation of the respective detonating device and the operation of the electroresponsive ignition means therefor.

The member 73 is recessed as at 99 to receive a shock proof arming switch generally indicated by the reference character 101 and comprising a body portion 102 formed of a plurality of discs 103 and composed of any insulating material suitable for the purpose such, for example, as Bakelite, each of the discs having a bore 104 therein as more clearly shown on Figs. 8 and 13 through which the tubular member 36 is adapted to move during the arming of the fuze. Disposed between the disks 103 and in spaced relation with respect to each other is a plurality of annular members 105, 106, and 107, each member having formed thereon and extending inwardly and downwardly therefrom a plurality of spring contacts 108, Figs. 10 and 15. As clearly shown on Figs. 8 and 10 the contacts 108 are in engagement with the insulating sleeve 86 when the rod is in the initial locked position. As the rod 85 moves toward the released position, the insulating sleeve 86 is disengaged from the spring contacts 108 and the contacts are brought into engagement with the contact sleeve 87. Each annular member 105, 106, and 107 has formed thereon a terminal designated by the numerals 109, 111, and 112 respectively, the terminals being secured to the support 73 as by a screw 113 or the like, Fig. 9. By the aforesaid construction and arrangement a circuit is closed to the detonating devices 76 and 77 when the fuze is in an armed condition as will more clearly appear as the description proceeds. As shown more clearly on Figs. 3, 8 and 13, the discs and annular member are supported within a container 114 composed of suitable insulating material and having a flange 115 formed thereon, in abutting engagement with the lowermost member 107. The discs and annular members are clamped within the container by a circular plate 116, Fig. 8, disposed in abutting engagement with the aforesaid flange 115 and having a pair of diametrically arranged legs 117 integrally formed thereon and in clamping engagement with the outermost disc 103, and thus by the aforesaid arrangement a unitary and shock proof switch assembly is provided for the fuze. The container 114 is provided with a plurality of slots 118 for receiving the terminals 109, 111, and 112 respectively thereby to provide an external electrical'connection from the switch to the aforesaid coils and electroresponsive detonators.

The arming operation of the device will now be described. Let it be assumed, by way of example, that the bomb is released from an aircraft in flight. As the bomb falls away, from the aircraft the arming wire 13 is withdrawn thereby releasing the propellers 15 and 16 for rotation. When the propeller 16 has made a predetermined number of revolutions during the free flight of the bomb I through the air, the shaft 43 is rotated by the aforesaid planetary gearing sufficiently to cause the shaft to be detached from the rod 31 whereupon the arming assembly comprising shaft 43, propeller 16 and shield 55 falls away from the fuze. When this occurs, the arming switch contacts are closed thereby completing a firing circuit between the coil 29 and detonating device 77 and an additional firing circuit between the coil 23 and the detonating device 76, Fig. 15. Concurrently with the closing of the arming switch contacts, the rod 85 is moved forward by the spring 91 suflicie'ntly to release the.detonator holder 82. The detonator holder is moved to thearmed position 2 by spring83. with the sensitive detonating' cap,92. thereof in substantial abuttingirelation with-thevleacl-inv charge 93 and in readiness to be fired by'either'of the detonating devices 76 and'77 as the case may be; The bomb is now armed.

Let it now be assumed that the bomb is dropped from an aircraft in flight from a relatively low altitude such,

for example, as 200 feet, misses the target vessel, and

strikes the surface of a body of water at a point adjacent thereto. As the bomb strikes the surface of the water, the magnetic core assembly 33 is suddenly moved rearwardly toward the support 13 and coil 23'against the action of the aforesaid spring members 27. When this occurs the air gap between the bar magnets 26 and the support 19 is suddenly decreased whereupon theresulting change in the magnetic field linking coil 23 generates an.

electromotive force within the coil of sufficient strength to ignite the detonating device76. The detonating device 76, it will be recalled, is adapted to fire the bomb when a period of .25 second has elapsed after the electrical firing impulse thereto has been received. The bomb is thus fired at a predetermined depth such, for example, as 30 feet below'the surface of the Water at which the air cavitation within the water above the bomb has been reduced sufficiently to effect the most efficient transmission of the force of the explosion through the surrounding water and thereby cause the maximum damage to the vessel.

In the event that the bomb strikes the hull of the vessel during this underwater travel, the detonating device 77 is ignited by the front coil 29 of the fuze and the bomb is exploded, either adjacent the hull of the vessel or within the hull of the vessel, as the case may be, when a period of time of .01 second has elapsed after the bomb strikes the hull. If the bomb didnot strike the vessel during its underwater travel prior to the lapse of .25 second, the hydrostatic tail fuze 17 causes the bomb to fire when the bomb reaches a predetermined depth of submersion such, for example, as 35 feet.

It will be understood, however, that the fuze of the present invention is also adapted to be fired by a change in the number of flux linkages of the front coil as the fuze moves into close proximity to a target composed of magnetic material such, for example, as the deck of a vessel, or in the event that the bomb strikes a non-ferrous target with sufficient force to dislodge the permanent magnetic structure from the magnetic body supporting the front coil, or with only sufficient force to disarrange the :space relation of the magnets with respect to one another or to partially demagnetize the magnetic core.

When this occurs a firing impulse is generated by the rear coil of sufficient strength to ignite the aforesaid slow operating detonator and explode the bomb apredetermined period of time after the firing impulse'has been received.

Whereas the invention has been described in detail with respect to a bomb adapted to be dropped on av surface sponse to an electromotive force-generated within the coil and caused by a sudden change in the magnetic field linking the coil as the air gap between the floating bar magnets and thecoil support is decreased by movement of the bar-magnets with respect to the support upon. impact of the fuze with the surface of abody of water, in which means are provided for'firing the fuzein response" to a sudden variation in'the magnetic field disposed therein and. adjacent thereto as the fuze moves into proximate spaced relationwith respect to atmagnetic target; and .in which means are providedzforfiring.thetfuze in "the event that thetfuzestrikes thetarget with'snfficient force to de-' range or partially demagnetize the magnetic element therein regardless of the magnetic character of the target;

Furthermore, the present invention provides means for firing an explosive charge in predetermined time delayed relation with respect to the movement of the fuze into proximate spaced relation with respect to a magnetic target andfor firing the explosive charge in different time delayed relation with respect to the aforesaid movement, derangement or demagnetization of the magnetic element.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. the scope of the appended claims the invention may be practiced otherwise than as specifically described.

The invention described herein may be manufactured and used by or for Government of the United Statesof America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a fuze of the character disclosed, in combination, a segmented magnetic core slideably supported on said fuze and comprising a plurality of permanent bar magnets,

means composed of electrical insulating material for supporting said magnets in closely spaced relation with respect to one another, a mass of magnetic material, means including said supporting means for slideably supporting said core on the fuze with one end of each of the magnets in spaced relation with respect to said mass, a coil of wire disposed within said mass and substantially coaxially with respect to the axis of said core, and an electroresponsive detonating device operatively connected to said coil and constructed and arranged to be operated by the voltage generated within the coil as the core is suddenly moved toward the magnetic mass in response to impact of the core with the surface of a body of water.

2. In a fuze for a bomb adapted to be dropped from an aircraft in flight, the combination of a movable segmented magnetic core comprising a plurality of closely spaced permanent bar magnets arranged within the fuze, a mass of magnetic material arranged in spaced relation with respect to one end of each of said magnets, a coil of wire arranged within said magnetic mass, means including a resilient member for maintaining said one end of each of the magnets in spaced relation withsaid mass, means including a sleeve composed of nonmagnetic'material arranged about said core for detachably and slideably attaching the core to said fuze, and means including an electroresponsive detonating device operatively connected to said coil and constructedan'd arranged'to be operated by the voltage generated within the coil in response to the movement of the core with respect to said mented magnetic core comprising a plurality of closelyspaced permanent bar magnets arranged within the fuze, a mass of magnetic material secured to said fuze-in spaced relation with one end of each of said magnets'therebyto provide an air gap therebetween, means including a resilient member for maintaining said one end of each of the magnets in spaced relation with said mass, a coil of who arranged within said mass and adaptedto generate an electrical firing impulse as said air gap is decreased by movement of said core upon impact'of the bomb with I the surface of a body of water, means including a sleeve composed of nonmagnetic mate ial arranged about said core for attaching the core movably to said fuze, a:-n'ormally open firing circuit connected to said coil, anelectro-'- responsivedetonating device included within said firing circuitfor firing the bomb in response to said electrical It is therefore to be understood that within ported at the forward end of said core for closing the firing circuit during the free flight of the bomb through the air after the bomb has been released from the aircraft.

4. In a bomb fuze of the character disclosed, the combination of a segmented magnetic core comprising a plurality of closely spaced bar magnets movably arranged within the fuze, a coil of wire disposed about one end of the core, a mass of magnetic material arranged in spaced relation with the other end of the core, means for movably supporting the core within the fuze, a second coil arranged within said magnetic mass in substantial coaxial relation with respect to the core, and a pair of electroresponsive devices respectively connected to said coils, said first named coil being adapted to generate a voltage therein sulficient to operate the electroresponsive deviceconnected thereto in response to the sudden increase in the flux in said one end of the core as the bomb moves into close proximity with a target composed of magnetic material, and said second coil being adapted to generate a voltage therein suificient to operate the electroresponsive device connected thereto as the flux in said other end of the core is suddenly increased in response to the movement of said core with respect to the mass upon impact of the bomb with the surface of a body of water.

5. In a fuze for a bomb adapted to be dropped from an aircraft on a target, the combination of a movable segmented magnetic core comprising a plurality of closely spaced bar magnets arranged within the fuze, a coil of wire arranged about one end of the core, a mass of magnetic material in spaced relation with the other end of the core, means including a resilient member for movably supporting the core to the fuze, a second coil arranged within said magnetic mass in substantial coaxial relation with respect to the core, and a pair of electroresponsive devices respectively connected to each of the coils, said first named coil being adapted to generate a voltage therein sufficient to operate the electroresponsive device connected thereto as the core approaches and strikes a target composed of magnetic material, said second coil being adapted to generate a voltage therein sufficient to operate the electroresponsive device connected thereto as the flux in the other end of the core is suddenly increased in response to the movement of the core with respect to the mass upon impact of the core with the surface of a body of water.

6. In a fuze for a bomb adapted to be dropped on a target from an aircraft in flight, the combination of a movable segmented magnetic core comprising a plurality of closely spaced permanent bar magnets arranged in the fuze, a bomb casing, a mass of magnetic material arranged in spaced relation with respect to one end of said core'for supporting the fuze on the nose of said casing, means including a sleeve secured to said mass for movably supporting the magnetic core on the fuze, a coil of wire disposed within said mass and adapted to generate an electrical firing signal in response to a sudden increase in the magnetic flux within the coil when the core is moved toward the mass upon impact of the core with the surface of a body of water, a second coil arranged about the otherend of the core and adapted to generate an electrical firing signal as the bomb moves into proximate relation to a magnetic target, a pair of electroresponsive detonating devices respectively connected to said coils and constructed and arranged to be detonated in predetermined time delayed relation with respect to each of said firing signals respectively, a percussion sensitive detonating cap fired by either of said detonating devices, and an explosive charge disposed within the casing and fired by said detonating cap.

7. In a fuze for a bomb adapted to be dropped on a target from an aircraft in flight, the combination of a movablefsegmented magnetic core comprising a plurality of closely spaced permanent bar magnets supported on said fuze, means including a magnetic support arranged in spaced relation with respect to one end of said core for securing the fuze to the nose of the bomb and for movablysupporting said core, means including a resilient member for maintaining said core spaced from the magnetic support, a pair of electroresponsive detonating devices within coil arranged about the opposite end of the core for generating-an electrical firing impulse suflicient to operate the other one of the detonating devices as the fuze moves into proximate relation with a magnetic target and without making contact therewith, a second normally open firing circuit including said second coil and said other one of the detonating devices, means including a normally locked propeller constructed and arranged to close said firing; circuits when the propeller has been unlocked and ro tated a predetermined number of revolutions during the movement of the bomb through the air, and means including an arming wire secured to said aircraft for unlocking the propeller as the bomb moves away from the aircraft. I

8. A water discriminatingmagnetically controlled fuze for a bomb comprising a movable segmented magnetic core composed of a plurality of closely spaced permanent bar magnets, means including amass of magnetic material disposed in spaced relation with one end of the core for movably securing the core to the mass, means including a resilient member for maintaining said core in initially electroresponsive detonating device within the fuze and adapted to fire the bomb, a coil of wire arranged within said magnetic mass in spaced relation with said one end of the core for generating an electrical firing impulse sufficient to operate said detonating device when the core is moved toward the magnetic mass upon impact of the core with the surface of a body of water, a normally open firing circuit including said coil and said detonating device, a releasably locked propeller rotatably supported on the nose of the fuze, and means including a plunger slideably arranged in the fuze for closing said firing circuit when the propeller has been released and rotated a predetermined number of revolutions during the movement of the bomb through the air.

9. A water discriminating magnetically controlled fuze for a bomb comprising a movable segmented magnetic core composed of a plurality of closely spaced permanent bar magnets, a casing composed of nonelectrical conducting material for supporting said magnets in closely spaced relation with respect to one another and movable with the core, a mass of magnetic material disposed in spaced relation with one end of the core, means including a plurality of spring members for maintaining said core spaced from the mass, means including a flanged sleeve secured to the mass for movably supporting said core, an electroresponsive detonating device within the fuze for exploding the bomb, a coil of wire arranged within said mass in spaced relation with said one end of the core for generating an electrical impulse sufiicient to operate said detonating device in response to movement of the core toward the mass upon impact of the core with a body of determined number of revolutions, and means in engagement with the plunger and controlled by the propeller for preventing closing of said switch by the plunger until the ma ma 11 propeller has-made a predetermined number 'of'i'e'volutions.

10. A water discriminating magnetically controlled fine for a bomb comprising a movable segmented magnetic core composed of a plurality of closely spaced permanent bar magnets, a casing composed of nonelectrical conducting material for supporting said magnets in closely spaced relation with respect to one another and movable with the core, a mass of magnetic material disposed in spaced relation with one end of the core, means'ineluding a plurality of spring'members for maintaining the core spaced from the mass, means including a flanged sleeve secured to the mass for movably supportingsaid core, an electroresponsive detonating device within the fuze for exploding the bomb, a coil of wire arranged within said mass in spaced relation with'said one end of the core for generating an electrical impulse sufficient to operate said detonat ing device in responseto movement of the core toward the m'assupon impact of the core with a body of water, a normally open firing circuit including said coil and the detonating device, a cylindrical casing secured to themass and having a recess arranged therein, a normally open switch in said firing circuit and clamped within said recess by said mass, a plurality of spaced annular members arranged within said switch, a plurality of contacts on said annular members respectively, a propeller rotatably supported on the nose of the fuze, aplunger in engagement with said contacts for closing the firing circuit when the plunger is moved a predetermined distance, means in engagement with the plunger and controlled by the propeller for preventing the plungerfrom closing the firing circuit until the propeller has made a predetermined number of revolutions, and means formoving the plunger said predetermined distance.

11. A water discriminating magnetically controlled fuze for a bomb comprising a movable segmented magnetic core composed of a plurality of closely spaced permanent bar magnets, a casing composed of non-electrical conducting material for supporting said magnets in closely spaced relation with respect to one another and movable with the core, a mass of magnetic material disposed in spaced relation with one end of the core, an annular member in engagement with said casing, a plurality of spring elements on saidannular member for maintaining the core spaced from the mass, means including a flanged sleeve secured to the mass for movably supporting the core, an electroresponsive detonating device within the fuze for exploding the bomb, a coil of wire arranged within the mass in spaced relation with said one end of the core for generating an electrical impulse suflicient to operate said detonating device in response to movement of the core toward the massupon impact ofthe core with abody of water, a normally'open firing circuit including saidcoil and thedetonating device, a cylindrical member'cornposed of non-electrical conduetingmaterial secured to said mass and 'having a recessarranged therein, a container clamped within said recess by the mass, a plurality of annular members in said firing-circuit and disposed within said container in spaced relationwith respect to each other, aplurality of contactsarranged on each of said annular members respectively, a propeller rotatably supported on the nose'of the fuze, means including, a plunger in'engagement with said contacts for closing'the firing circuit when the plunger is moved a predetermined amount, means in engagement with the plunger and controlled by the propeller for preventing the plunger from closing the firing circuit until the propelier has made a predetermined number of revolutions, and means including a spring for moving thetplunger said predetermined amount. I

12.. In a fuzefor a bomb-adapted to be dropped on a target from an aircraft in' flight, the combination of a" movable segmented magnetic core comprising a plurality of clos ely'spacedpermanent barm'agnets supported on said fuz'e, means including amagnetic support arranged in spaced'r'elation withone end of said core for secur ing the fu zeto the nose of the bomb and for movably supporting the core, means including a resilient member for maintaining said core spaced from the magnetic support, -a pair ofelectro-responsive detonating devices within the fuze and adapted to fire thebomb, a coil of wire arranged within said magnetic support in spaced relation with said one end of the'core for generating an electrical firing impulse when the core is moved toward the magnetic support upon impact of the core with the surface of a body of water, a normally open firing circuit including said coil and one of said detonating devices, a second coil arranged about the opposite end of the core for vgenerating anelectrical firing impulse suflicient to operate the other one of the detonating devices as the fuze moves into proximate relation with a magnetic target without making contact therewith, a second normally open firing circuit including said second and said other 7 one of the detonating devices, a normally open switch 20" arranged within'the firing circuits and comprising a plurality of contact elements, said switch being clamped within the fuze by, said mass,"means including a plunger in engagement with said contacts for closing said firing circuits when the plunger is moved a predetermined "amount, a propeller rotatably supported on the nose of the fuze, means in engagement with the plunger and controlled by'said propeller for preventing the plunger from closing said firing circuits until the propeller has made aprede't'ermined' number of revolutions, andmeans including'aresilient-element for moving the plunger said predetermined amount.

13. In a fuze for a bomb adapted to be dropped on; a target from an aircraft in flight, the combination of a movable magnetic core arranged within said fuze, a pair 'of electro-responsive devices, a coil disposed about one end of the core and connected to one of the electrorespon sive devices for generating a voltage suflicient to operate said one device as thebomb moves into proximate relation with a target composed of magnetic material, a mass of magnetic material arranged in spaced relation with the other end of the core, and a second coil arranged within said magnetic mass and connected to the other meet the electroresponsive devices for generating -a voltage sufficient to operate said other device in response to-movement of the core with respect to themass a coil arranged within said mass in spaced relation with said one'end'of the core for generating an electrical firing impulse when the core is moved toward the magnetic mass upon impact of the core with the surfaceof a body of Water, a' normally open firing circuit including said coil andcne of said detonators, a second coil arranged about the core for generating an electrical firing impulse sufiicient to pperate the other one of the detonators as the fuze movesinto proximate relation with a magnetic target, and meansincluding a propeller for closing said flringcircuit when the bomb has been dropped from said aircraft and the propeller has made a predetermined number' of revolutionsduring the free flight of the bomb toward the target.

References Cited in the 'file of this patent UNITED STATES PATENTS 2,404,553 Wales -l July 23, 1946 FOREIGN PATENTS 2,326" GreatfBritain of 1885 525,333 Great Britain Aug. 27, 1940 

